The invention relates to felts for use in papermaking machines, and has to do more particularly with felts for removing water from a paper sheet while the sheet is supported on and carried by the felt.
Various techniques have hitherto been proposed for removing water from a paper sheet, the most common being by the use of a press, wherein the paper sheet and the felt on which it is carried are squeezed between rollers, the felt being formed in such a manner that the water extracted from the paper will pass through the felt for discharge. Desirably, the press felts are woven so as to have relatively large open areas or voids which will enhance their water conveying capabilities so that the water may be removed from the felt upon passage over a suction box. The press felt normally has a conveyer belt-like shape and during the various operations previously mentioned, a large amount of water is built up in the press felt which is removed by suction or various other drainage devices, usually after the paper web and press felt are no longer in direct contact.
The ideal papermaking felt should have at least the following properties. First, it should have a surface that is fine enough to produce a smooth finish and minimize marking of the sheet of paper being produced. Second, it should be open enough to allow water to drain through it without significant impedance. Third, it should be resilient enough to quickly recover from repeated high nip pressures over a long period of time. Fourth, it should be tough and strong enough to provide good stability, wear resistance and felt life.
It has been found that a papermaker's felt having a base fabric with a high vibration absorption capacity compared to the usual dual layer fabrics provides better runnability, fewer maintenance stops and improved paper quality.
Accordingly, is an object of the present invention to provide a fabric for use in papermaking machine having improved vibration absorption capacity.
It is a further object to provide a felt having high elasticity and resilience to assure better runnability, less maintenance stops and improved paper quality.
It is a further object of the invention to provide a papermaker's felt with improved dewatering performance.
It is another object of the present invention to provide a felt having longer lasting resiliency for better wet felt performance on heavily loaded, high-speed positions.